Fix NPE in registry_tool when creating or updating a TLD with a dns writer

I forgot to inject the CreateTldCommand/UpdateTldCommand commands, which now
need to be injected so that the list of available DnsWriter implementations is
instantiated. This CL also adds a new DI Set<String> with just the name of the
writer, so that the instantiated writer map (which may have many DI dependencies)
doesn't need to be pulled in.

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=130042215

java/google/registry/tools/BUILD

@@ -46,6 +46,8 @@ java_library(
         "//java/google/registry/bigquery",
         "//java/google/registry/config",
         "//java/google/registry/dns/writer",
+        "//java/google/registry/dns/writer/clouddns",
+        "//java/google/registry/dns/writer/dnsupdate",
         "//java/google/registry/export",
         "//java/google/registry/flows",
         "//java/google/registry/keyring/api",